Well this was interesting. My wife’s 2013 C-max would not start, stranding her on an errand. Car was totally dead. But when I hooked up jumper cables, it started immediately and she was able to drive home.
Next day, same issue.
I tried the key fob waving but that did nothing.
Next step was to remove the 12V battery and have it checked. But when I opened the hatch and removed the trim, I found that the 12V battery compartment was completely full of water. As in, up and over the battery terminals. (See pics)
My plan from here is to remove the water, remove the battery and have it checked and replaced if necessary, clean up the bits of corrosion, and find the source of the leak and fix that.
Other than those steps, does anyone recommend anything else (assuming that addresses the issue of not starting.)
I thought I would document here since I have not seen this problem reported before.
Lacienega reacted to a post in a topic:
Water in 12V battery compartment!